The Proteomics Facility Core (PFC) was developed in recent years because of a deep need by investigators for a systematic analysis of proteins for identity, quantity and function via state-of-the-art mass spectrometric measurements coupled to innovative biochemical tools and techniques. As such, the overall objectives of the Proteomics Facility Core are to provide support in proteomics research to Southwest Environmental Health Sciences Center (SWEHSC) and Arizona Cancer Center (AZCC) investigators, with the following specific aims: 1. In identifying and characterizing proteins and peptides and their modifications; 2. In implementing current proteomic protocols and methods when available; 3. In designing proteomics experiments and interpreting data.